This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study proposed to study methamphetamine using adults using PET imaging during early withdrawal (2 weeks and <3 months) and again 6-9 months later. The PET imaging will be conducted at Brookhaven National Laboratories in New York under the direction of Dr. Nora Vollow. Methamphetmaine is not a drug commonly abused in the eastern U.S. Hence, recruting for the 40 subjects will occur in Los Angeles at Harbor-UCLA and Portland, Oregon where methamphetamine abuse is a significant problem. Normal controls will not be recruited at the Harbor-UCLA site. The subjects will be recruited, screened, consented and then flown to New York for the neuroimaging studies. This project is an extension to previous work conducted at Harbor-UCLA funded by an NIH/NIDA RO1 grant (Brookhaven National Laboratory Subcontract), 10/01/97-11/30/00. The working hypotheses are: 1) METH abusers will have decreased function of DA cells in addition to the loss of DAT. 2) Detoxification will result in an increase in DA cell function and in DAT levels. It is important to assess if there is disrupted DA cell function in METH abusers since it could perpetuate METH use as a means to temporarily compensate for this dysfunction. It is also of relevant to determine if it recovers with detoxification in order to understand the long-term consequences of DAT losses in the METH abusers vis-a-vis their vulnerability to neurogenerative diseases (i.e., Parkinson's disease). Such knowledge should help guide the management of the METH abuser and the development of medications that may help ameliorate the DA deficits.